I love it when chabad says that a few gedolim who wrote letters to the lubavitcher rebbe and referred to him with titles means anything – talk to people who knew rav moshe. I did; many of my rebbeim were talmidim of his, and none had a favorable view of the lubavitcher rebbe.
It’s not as if rav moshe wrote that the lubavitcher is reliable, or sent someone to him. He didn’t.
I asked rav belsky once about why rav moshe used titles when writing to him. (Rav belsky used to say very harsh things against the lubavitcher rebbe, and there’s no point in mentioning them here. He also was extremely close to rav moshe.)
He said that rav moshe did everything he could to have his psakim accepted in klal yisroel, because he knew that it was necessary. He grew payos so that heimishe yidden would not repel him, and was warm with lubavitch and others for the same reason. He wasn’t a particular misnaged to chasidus in general, nor was he chasidish.
As for rav noson vachtfogel and….rav forcheimer? Different doros…not fit to be lumped together, but it any case, i have no idea if they were misnaged to chasidus in general, but they aren’t known to have said anything in contradiction to rav aharon and subsequent roshei yeshiva in Lakewood who openly consider lubavitch to be chutz lemachaneh.
But it’s not a chidush if someone is not a misnaged. Most gedolim after the kotzker rebbe were no longer opposed, once some of the more controversial practices were stopped and it became clear that chasidim in general, and especially polisher chasidim, were keeping normative Judaism.
There were and are a minority of gedolei yisroel who are still outwardly or quietly misnagdishe, but the problem is that in lubavitch, “misnaged” doesn’t mean someone who is against chasidus, it means someone who is against neo-chabad chasidus….and in that regard, it’s the vast majority. And many who initially were pro-chabaf, including rav avigdor miller and rav pam, changed their views when the issues came to light.